The invention relates to a cleaning apparatus and to a method for cleaning articles. The invention further relates to a use of a reactive gas, generated by a plasma source from at least one gas, for cleaning articles in a cleaning apparatus. Cleaning apparatuses, methods, and uses of this type are used in particular in the field of rinsing technology in order to clean articles, in the form of dinnerware, such as plates, cups, glasses, bowls, serving dishes, cutlery, trays and other objects that are used for the preparation and/or presentation and/or storage of food. Cleaning apparatuses of this type are used, for example, in large professional kitchens, for example, in large professional kitchens of company canteens, hospitals, care homes, government agencies, schools, or universities. In another embodiment, the cleaning apparatus, the method, and the use can also be used in the field of the cleaning of articles in the form of care utensils, such as pans, bedpans, urine bottles or similar care utensils, which come into contact with human or animal excretions. In a further possible embodiment, the cleaning apparatus, the method and the use can be used, for example, in order to clean other types of articles, for example, pieces of equipment belonging to personal protective equipment of rescue workers or divers, such as protective breathing masks, breathing masks, oxygen cylinders, diving regulators, snorkels, masks or similar pieces of equipment. In a further possible embodiment, the cleaning apparatus, the method, and the use can be used, for example, in order to clean food, in particular fruit and vegetables and particularly preferably salad. Other fields of use are conceivable however in principle.
A large number of cleaning apparatuses for cleaning different types of articles are known from the prior art. For example, cleaning apparatuses of this type in the form of dishwashers, in particular for commercial use, are known from DE 10 2004 056 052 A1. Cleaning apparatuses in the form of what are known as cleaning and disinfection units, by means of which care utensils for care needs can be cleaned, are likewise described. Dishwashers, for example, in particular for commercial use, are known from DE 10 2006 050 876 A1. Dishwashers which are designed as pass-through dishwashers and in particular as multi-tank dishwashers are likewise known from DE 10 2006 039 434 A1. Further types of cleaning apparatuses in the form of cleaning and disinfection units are known, for example, from DE 103 48 344 B4 or from EP 1 824 373 B1.
It also known from the above-described prior art that increasing importance is ascribed to the guarantee of disinfection of the articles. In particular in hygiene-critical areas, such as hospitals or nursing care facilities, but also in areas of a communal feeding space, in particular in large professional kitchens, sanitization of the articles must be guaranteed.
Disinfection processes in cleaning apparatuses, for example, in dishwashers or cleaning and disinfection machines, are generally known from the prior art as thermal disinfection steps. Thermal disinfection of this type is generally performed by means of hot aqueous liquids and/or by means of steam. The disinfection medium used here is either introduced in an undirected manner into a cleaning chamber and delivers its heat content to the articles, or the medium is sprayed directly onto the articles, wherein a heat content is likewise delivered. This is described, for example, in the above-mentioned documents DE 103 48 344 B4 and EP 1 824 373 B1 and also in DE 10 2004 056 052 A1. Thermal disinfection processes of this type are likewise described in DE 10 2004 056 052 A1 for dishwashers, or, for pass-through dishwashers, in DE 10 2006 039 434 A1, for example.
Furthermore, disinfection methods that are performed using chemical agents, and also combinations of thermal and chemical disinfection methods are also known and are widespread. A method and an apparatus with which a disinfection effect is achieved by a combined use of UV light and/or by the use of ozone generated by a UV radiator, are also known from DE 10 2006 050 876 A1.
The apparatuses and methods known from the prior art present a series of technical challenges and disadvantages. A disadvantage in particular of the thermal disinfection methods lies in a relatively high use of energy to heat the media used for the disinfection. For example, in many cases, liquid media are heated to 90° C., for example. Alternatively or additionally, steam has to be produced as a disinfection medium in many cases. An increased use of energy is generally also accompanied by a relatively long process duration. A further disadvantage lies in the fact that, at the end of the disinfection process, the articles are generally very hot and first have to be cooled again, thus eliminating the risk that an operator will injure himself by touching the hot articles.
By contrast, chemical disinfection methods function using generally aggressive chemicals. These can cause ecological problems or can pose health risks during use and/or in the event of disposal. In addition, in many chemical disinfection methods used on dinnerware and similar objects that are used for the preparation, presentation or storage of food, the articles may be tainted by an unpleasant taste. In particular when cleaning drinking glasses, chemical disinfectants, for example, in many cases produce an adhering chlorine taste and/or chlorine smell, which is undesirable.
Furthermore, plasma sources for disinfection purposes are known in particular from the medical field. For example, an electrode arrangement for producing a non-thermal plasma is known from WO 2010/094304 A1. This electrode arrangement comprises a layer-shaped first electrode produced from an electrically conductive material, and a layer-shaped second electrode produced from an electrically conductive material, wherein the second electrode is electrically insulated from the first electrode. Furthermore, a dielectric barrier is arranged between the first electrode and the second electrode, such that the non-thermal plasma is generated by a dielectric barrier discharge. At least one of the electrodes comprises a plurality of perforations, which are distributed over the electrode. EP 2 170 022 A1 and WO 2010/034451 A1 describe an apparatus for applying a plasma to human skin, for example. WO 2010/094307 A1 describes an apparatus for the plasma treatment of body parts, and EP 2 160 081 A1 describes an apparatus for application of a plasma, wherein additional substances are added to the plasma in order to influence the effect. Further embodiments of plasma sources are described in EP 1 993 329 A1 and in EP 1 765 044 A1.
A method for textile cleaning and textile disinfection by means of plasma is described in DE 102007037984 A1. A plasma source for sterilizing PET bottles is also known from the publication Verfahrenstechnik (Process Engineering) 1-2/2010, page 12. In this case a pin is used, which generates a plasma jet. For example, plastic films and/or other types of packagings can be treated and thus sterilized by means of this plasma jet.